86 rough running.
Thread Starter
Instructor
Joined: Apr 2004
Posts: 115
Likes: 2
From: Kissimmee, FL
86 rough running.
I have an 86 that is hunting at idle. Running rough between 5 and 7 K RPM at idle. Also runs rough when driving, like it is missing. Fuel pump and injectors tested OK. New MAF, plugs, wires, dist. cap and fuel filter. Was told it could be the TPS or vac leak. Runs a little smoother when disconnected.
Thanks, JD
Thanks, JD
Burning Brakes
Joined: Aug 2010
Posts: 833
Likes: 1
I would think these engines would run a bit rough at 7k rpm. I just replaced the injectors in my 86, and it idles very smoothly now, and it feels stronger when accelerating. Call jon at FIC he'll hook you up with some injectors if that's the way you want to go. Also, check timing, check for codes etc..
Racer
Joined: Nov 2010
Posts: 460
Likes: 1
From: Oliphant Ontario
There are a ton of threads on this board you can search and read through covering rough running but intake air leaks, dirty IAC's, wrong intitial timing, dirty injectors and improper setting on TPS are by far the most common.
You say it runs smoother when disconnected, but you don't say what is disconnected unless you mean the TPS, it should throw a code running that way and have little or no throttle response..
You say it runs smoother when disconnected, but you don't say what is disconnected unless you mean the TPS, it should throw a code running that way and have little or no throttle response..
Thread Starter
Instructor
Joined: Apr 2004
Posts: 115
Likes: 2
From: Kissimmee, FL
Yes, when TPS diconnected, throws a code. Replaced TPS, not as much idle hunting. Now idles between 600 and 700. Checked for vac leaks. Fuel inj. checked out OK. Timing OK and MAF was replaced. Cleaned throttle body too. I will check the IAC.
Team Owner
Joined: Jan 2003
Posts: 20,324
Likes: 250
From: Summerland B.C. Canada
You may want to try and set your minimum idle and TPS idle voltage.
http://www.lbfun.com/warehouse/tech_...ch%20Paper.pdf
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